Ah! The best success was gained with:
Code:
zmmailbox -a admin -p password -m mailboxowner@domain.com createMountpoint --view appointment "/Meeting Room Calendar" meetingroom@domain.com /Calendar
That caused the Meeting Room Calendar to appear in the user's Calendar screen.
Less important, but... when the share was deleted in the UI, the mountpoint remained. How can the mountpoint be deleted?
Thank you!